Herbicidal imidazolin-2-yl pyridine and quinolinecarboxylic acids, esters and salts of formula I below, methods for their preparation and use are described in European Patent Application No. 81103638.3, published Dec. 16, 1981 and pending application for U.S. patent, Ser. No. 616,747, filed June 4, 1984 ##STR1## wherein X is H, halogen, methyl or hydroxyl;
Y and Z are each hydrogen, halogen, C.sub.1 -C.sub.6 alkyl, hydroxyloweralkyl, C.sub.1 -C.sub.6 alkoxy, C.sub.1 -C.sub.4 alkylthio, phenoxy, C.sub.1 -C.sub.4 haloalkyl, nitro, cyano, C.sub.1 -C.sub.4 alkylamino, diloweralkylamino or C.sub.1 -C.sub.4 alkylsulfonyl group, or phenyl optionally substituted with one C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 alkoxy or halogen, difluoromethoxy, trifluoromethoxy, 1,1,2,2-tetrafluoroethoxy, C.sub.3 -C.sub.8 straight or branched alkenyloxy optionally substituted with one to three halogens, or C.sub.3 -C.sub.8 straight or branched alkynyloxy optionally substituted with one to three halogens; PA1 R.sub.1 is C.sub.1 -C.sub.4 alkyl; PA1 R.sub.2 is C.sub.1 -C.sub.4 alkyl or C.sub.3 -C.sub.6 cycloalkyl; and when R.sub.1 and R.sub.2 are taken together with the carbon to which they are attached they may represent C.sub.3 -C.sub.6 cycloalkyl optionally substituted with methyl; PA1 R.sub.3 is hydrogen or COOR.sub.3 represents a salt or ester of the acid. PA1 Y and Z are each hydrogen, halogen, C.sub.1 -C.sub.6 alkyl, hydroxyloweralkyl, C.sub.1 -C.sub.6 alkoxy, C.sub.1 -C.sub.4 alkylthio, phenoxy, C.sub.1 -C.sub.4 haloalkyl, nitro, cyano, C.sub.1 -C.sub.4 alkylamino, diloweralkylamino or C.sub.1 -C.sub.4 alkylsulfonyl group, or phenyl optionally substituted with one C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 alkoxy or halogen, difluoromethoxy, trifluoromethoxy, 1,1,2,2-tetrafluoroethoxy, C.sub.3 -C.sub.8 straight or branched alkenyloxy optionally substituted with one to three halogens, or C.sub.3 -C.sub.8 straight or branched alkynyloxy optionally substituted with one to three halogens; PA1 R.sub.1 is C.sub.1 -C.sub.4 alkyl; PA1 R.sub.2 is C.sub.1 -C.sub.4 alkyl or C.sub.3 -C.sub.6 cycloalkyl; and when R.sub.1 and R.sub.2 are taken together with the carbon to which they are attached they may represent C.sub.3 -C.sub.6 cycloalkyl optionally substituted with methyl; PA1 R.sub.3 is H or COOR.sub.3 represents an ester of the acid; PA1 R.sub.4 and R.sub.5 are each C.sub.1 -C.sub.4 alkyl or phenyl or when taken together, may form a C.sub.5 or C.sub.6 cycloalkyl; PA1 R.sub.1 is C.sub.1 -C.sub.4 alkyl; PA1 R.sub.2 is C.sub.1 -C.sub.4 alkyl; PA1 R.sub.3 is hydrogen, loweralkyl optionally substituted with phenyl; PA1 R.sub.4 is C.sub.1 -C.sub.4 alkyl; PA1 R.sub.5 is C.sub.1 -C.sub.4 alkyl or phenyl; PA1 X is H; PA1 Y is hydrogen or C.sub.1 -C.sub.4 loweralkyl; PA1 Z is hydrogen; PA1 R.sub.1 is methyl; and PA1 R.sub.2 is isopropyl.
and when taken together, Y and Z may form a ring which may optionally be substituted, in which YZ are represented by --(CH.sub.2).sub.n --, where n is an integer of 3 or 4, or (CH).sub.4 ;